Thermoluminescence kinetic parameters of beta irradiated the zinc gallate phosphor using different methods

Abstract

The ZnGa2O4 phosphor material was synthesised through the gel combustion method, and its structural characteristics were studied via X-ray powder diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX). The XRD result indicates the generation of ZnGa2O4 in spinal cubic phase with a 25 nm crystalline size. The synthesized phosphor was irradiated using a90Sr/90Y source with a dose range of 0.1 Gy–100 Gy. For measuring thermoluminescence (TL), a linear heating rate of 2 °Cs−1 was applied to the sample in a temperature range of 25 °C–450 °C. The TL experiment revealed two peak maxima located at 180 °C and 304 °C and a shoulder around 70 °C. By preheating at 110 °C, the low temperature peak at 70 °C is removed. Both the depth and frequency factors of electron traps were determined using various heating rates (VHR), Tm-Tstop combined with initial rise (IR), and Computerised Glow Curve Deconvolution (CGCD). In both the Tm-Tstop and CGCD methods, six overlapping glow peaks were detected below the main glow peaks. The calculated activation energy values and peak maximum temperatures agree well with each other. The depths of electron traps calculated by different methods were found to be between 0.4 and 1.4 eV. We observed that both peak maximum temperatures and the area under glow peaks gradually decreased with an increase in the heating rate. Both Peak 1 and Peak 2 show sublinear relationship between 0.1-5Gy and 10–100 Gy. The findings of the present study show that the phosphors can serve as effective TLDs.